SCHOTT solutions no. 1/2014 > Cabin Lighting
With the Eye of a Sensor
With ”HelioJet” Spectrumcc, SCHOTT and Lufthansa Technik are introducing an innovative LED cabin lighting solution that renders light in a stable and homogeneous manner. For the first time ever, special sensor technology imitates the sensitive color perception of the human eye.
Dr. Haike Frank
Light and colors have a profound effect on how we feel and even our ability to judge situations. If we perceive the lighting inside an airplane to be perfect, we will view the cabin as a whole as being of high quality. ”Often we don't even notice that our moods are directly related to the current lighting conditions. Our eyes, on the other hand, are extremely sensitive and register differences in color. Our brains immediately assess the results as being comfortable or uncomfortable,” Dr. Armin Plichta, General Manager of Transportation at SCHOTT Lighting and Imaging, explains. The new LED cabin lighting solution ”HelioJet” Spectrumcc (Color Control), developed by SCHOTT in collaboration with Lufthansa Technik and the sensor manufacturer MAZeT, leverages these scientific findings. This solution is based on a special optical light guide made of glass at the ends of which four LEDs – red, green, blue and white (RGBW) – each feed colored light. Up to three of these rods form one ”HelioJet” unit. Before they are emitted, the individual primary LED colors are mixed into a desired even color shade inside the light guide – an advantage over conventional LED strips that are unable to fully hide their inhomogeneous light point design despite indirect guidance of the light and diffusers.
Furthermore, ”HelioJet” Spectrumcc uses precise sensor and control technology that measures and controls the respective color shade of every LED extremely accurately and compares it with the target values for all ”HelioJet” units. ”True Color Sensors” are installed right next to the LEDs to perform this task. The core of each sensor consists of small facets that imitate how the human eye perceives colors by using a dichroic coating. ”This is truly sophisticated technology because our eye recognizes and distinguishes between color shades within an extremely narrow and complex spectrum,” emphasizes Fred Grunert, Managing Director of MAZeT. Nevertheless, LEDs in particular cause visible deviations in color due to their unstable rendering of color. They also age at different speeds, due in part to the local temperature stresses inside the narrow compartments in the airplane. “This explains why other lighting systems that do not measure and control every LED are unable to produce a constant color impression over the long term,” Dr. Plichta notes. ”HelioJet” Spectrumcc also scores points due to how little maintenance it requires and the fact that individual LEDs can be replaced. Furthermore, the LEDs have a longer lifespan of at least 50,000 hours (mean time between failures). The new solution is already sparking interest: SCHOTT is currently discussing an initial reference project with several airlines. <
”HelioJet” Spectrumcc is based on a special optical light guide that is made of glass. Four light diodes each feed in colored light – red, green, blue and white – at its ends. Precise sensor and control technology measures and regulates the main color shade of each LED across all of the ”HelioJet” units. Photo: SCHOTT